If you really think that a distributed filesystem (which is in fact what you need and there are some lighter ones that you could use, such as XtreemFS) is an overkill for you, then try something like Aspera.

GlusterFS is not that hard to set up. If you're using configuration management on those servers (you ARE using CM tools, right?), it should be trivial to set up the servers, set up the volume, install the clients and mount it on every box.